Stirling engines might be the best way to harvest the power provided by the sun
Nearly 200 years after their invention, and decades after first being proposed as a method of harnessing solar energy, 60 sun-powered Stirling engines are about to begin generating electricity outside Phoenix, Ariz., for the first time. Such engines, which harness heat to expand a gas and drive pistons, are not used widely today other than in pacemakers and long-distance robotic spacecraft.
The 1.5 megawatt (MW) demonstration site, known as Maricopa Solar, is set to begin operations early January 2010, with units provided by the Arizona-based Stirling Energy Systems (SES). While 1.5 MW is only a fraction of the power that may be generated at sites SES has contracted to develop in California and Texas, spokesperson Janette Coates says this is a necessary first step in the technology’s commercialization. “It’s important for our industry to see—and our partners and investors—that we can take a small-scale plant and get it operational before we break ground on larger ones,” she says.
That’s because Stirling heat engines have a reputation for being a bit impractical. First invented by Robert Stirling in 1816, the engines use a heat source to warm gas, which expands and is pushed into another chamber. When the gas cools and contracts, it flows back. The expansion and contraction pushes a piston, which in turn produces electricity.
In 1996, SES bought solar Stirling design and engineering patents from companies such as McDonnell-Douglas and Boeing. SES then partnered with Sandia National Laboratories, and over the next decade tweaked and refined the technology. In the SES SunCatcher, a circle of curved mirrors, resembling an upturned satellite dish, tracks the sun on two axes and reflects the sun’s heat onto a single focus point, the power conversion unit (PCU). The PCU contains four cylinders, in which hydrogen gas expands and contracts to move pistons.
Stirling engines are significantly more efficient at converting sunlight into energy than most photovoltaic panels or concentrating solar power plants, whether parabolic trough or tower designs. The test units have reached 31 percent efficiency, compared to 16 percent for parabolic troughs and about 14-18 percent for PV panels in use today (though newer designs not yet on the market range from 24 to as high as 41 percent). The high efficiency numbers alone, however, have not made Stirling an easy sell. The systems have been criticized as being too expensive, unreliable and requiring extensive maintenance thanks to many moving parts. Also, ground has not yet been broken on either California site for which SES signed purchase power agreements in 2005, adding to skepticism that these systems will ever become commercially viable.
The Latest on: Stirling engines
[google_news title=”” keyword=”Stirling engines” num_posts=”10″ blurb_length=”0″ show_thumb=”left”]
via Google News
The Latest on: Stirling engines
- Building Conservation Week at the Engine Shedon May 9, 2024 at 5:41 am
The Building Conservation Week (10 – 14 June) is an intensive course delivered by experts in conservation, traditional skills and traditional building materials ...
- Powering homes with PVT energy, Stirling engines, battery storageon May 9, 2024 at 2:52 am
UK scientists have proposed a way to combine photovoltaic-thermal energy with Stirling engines and battery storage in residential buildings. Despite the high upfront costs, they said the ...
- Global External Combustion Engine Market Revenue to Surpass USD 889.0 Million Mark by 2032, Driven by a Steady 3.9% CAGRon May 8, 2024 at 6:38 am
The global external combustion engine market is poised to experience a robust Compound Annual Growth Rate (CAGR) of 3.9% throughout the forecast period. Initial projections suggest a market value of ...
- Submarine Game: Hangor Elevates Pakistan, China Stifles Indiaon May 3, 2024 at 9:05 pm
Pakistan recently enhanced its strategic position in the Indian Ocean and Arabian Sea by acquiring the first of eight advanced Hangor-class submarines from China. This development has been noted by ...
- Qnergy expands methane abatement project at closed Utah landfillon May 2, 2024 at 12:33 pm
After a successful pilot program, Weber County and Qnergy have expanded the project to abate more than 95 percent of methane emissions from the closed landfill.
- Thousands attend 22nd annual Stirling Street Fairon April 23, 2024 at 9:15 am
A crisp 65-degree day, with the smell of kettle corn, zeppoles, and meats wafting through the air, made the ideal environment for the 22nd annual Stirling ...
- Major new film and TV studio campus to be built in Stirlingon April 17, 2024 at 5:50 am
A major new film and television studio campus is to be created in Stirling. Stirling Studios will become one of the biggest media hubs in Scotland and is expected to pave the way for thousands of ...
- The Ultimate Guide To Search Engine Marketing (SEM) In 2024on April 17, 2024 at 5:04 am
Leeron is a New York-based writer with experience covering technology and politics. Her work has appeared in publications such as Quartz, the Village Voice, Gothamist, and Slate. Kelly Main is a ...
- UK Government Backs New Scottish Film & TV Studioon April 16, 2024 at 9:01 am
Stirling Studios will generate more than 4,000 jobs across several industries in 25 years, according to an independent economic impact assessment. The founders are calling Stirling “among the ...
via Bing News